Could be a bridge, a tunnel, a causeway or even a 'submerged floating tunnel'.
Resolves on undisputed media reporting
@StrayClimb I have quite a lot, but all mine are either 'crossings' or tunnels only and various dates. It's all good
The shortest distance between the two islands is 26km, and the shortest distance between the two islands that doesn't begin and end in mountainous or uninhabited hilly areas is 57km. The longest bridge over seawater is the Hangzhou Bay Bridge, at 35 km. The Cook Straight has some very fast and relatively deep water flows. Considering NZ's relatively high respect for the natural environment and relatively small population, I am confident NZ will not complete a bridge this long in the next 18 years.
@JoshuaWilkes I think a less uncertain market is whether NZ will start construction of an additional Auckland harbour cross before 2040. I'd bet yes but it is not a sure thing. On completing that crossing I think odds are fairly close to 50:50